Hello world! I have a custom 1000x1250 CNC router built on C-beam using delrin wheels, OB plates. 8mm leadscrews for the 1000mm axis and a belt drive for the long (X) axis. I'm thinking of doing away with the wheels and going with Hiwin-style linear rail and carriage blocks. However, those come in a variety of sizes from different manufacturers. I'm a little fuzzy on what size would be best for mounting to c-beam. Also, prices seem to be all over the board. I'd appreciate any size recommendations and links to reputable sources.
Here is a couple good places to start: 1510 Workbee Modified and if you go to "[Update: 1/17/19]" here: Shawn's Workbee 1510. I am in the middle of a modification I started 1.5 years ago. I got distracted and built 2 other machines instead of finishing the mod. ADHD for the win! Anyways, I am using the same blocks and rails as Jacob and Shawn. My brackets are different and are made from aluminum angle.
I got my rails from Amazon and were similar to this. https://www.amazon.com/Happybuy-15-...ab-b7a7-42a31a2787e5&pd_rd_i=B06VVXT19J&psc=1 My Y axis is 1500mm. I disassembled the bearing blocks and cleaned them then re-greased them with the recommended grease. There are several videos on how to do this. I highly recommend you never drop them on a concrete floor...repeatedly, or you will need to order some of these as well. https://www.amazon.com/gp/product/B007B2AIL6/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 DAMHIK.
Good advice given, I'd also recommend that you go ahead and order ball bearing before you eventually drop one or ten on the floor and can't find them.
Easiest size to mount is 20mm because it's a full V-Slot unit width. 15mm are much lighter, though, and will handle far more loading than the actual machine frame can. The "correct" size engineering-wise for light hobby aluminum extrusion machines is actually MGN12. It seems undersized, but as with all linear profile rail, it can take far more force than it seems- about 800lb of dynamic loading, 1500lb of static loading, and 3.5kg-m of static moment per block. When you consider the forces and torque moments at each point of the motion chain as the machine moves around, they're probably never going to be high enough to overload even one of these blocks, never mind the two or four that you'd actually use for mounting rigidity.
